Hannu2

It works also in Finnish. Grammar allows infinite number of substantives. There are many insane examples made to be examples but longest word actually used may be "lentokonesuihkuturbiinimoottoriapumekaanikkoaliupseerioppilas", which means "airplane jet turbine engine auxiliary mechanic non-commissioned officer student". Another option is to put insane number of suffixes, but then even Finns have to draw logic chart to understand the word. https://en.wikipedia.org/wiki/Longest_words#Finnish

Antiprotons consist of up and down antiquarks. So they can react straight with all baryons consisting of up or down quarks, like protons and neutrons. Annihilation of protons release about one GeV per particle and binding energies of nuclei are less than 10 MeV per baryon. I would guess that a nucleus which reacts with an antiproton will shatter to several fragments.

Simple scaling do not work in engineering. There are very fundamental problems. For example, if you increase size of something by a factor of 10, all volumes and masses increase by factor of 1000 and areas by factor of 100. If you have a strut, it must carry 10 times more mass per area. You have to change material. It affects also to energy production, flows, hydrodynamics and practically everything. If you scale your rubber duck to a kilometer size, it can not carry its own weight and is flat layer of rubber sheet on floor. That is the reason why there are arbitrary small or large machines. You can make them, but they do not work. Material strength is another problem. There are limited number of different atoms in our universe and bonds between them are known and they depend on electromagnetic interactions. They have limited strength. Therefore materials from which you can make hollow planets (or strut them) do not simply exist. You have to postulate whole new type of particles and physical interactions between them to get things which can strut hollow planets or store and handle energies of planet vaporizing lasers or act as rocket engine which moves planets. On that level you can say anything. In my opinion it would not be interesting scifi. Real planets are practically liquid spheres. They may have solid layers, but all solid materials act as liquids at pressures inside planets. If two planets collide, they merge as viscous liquid drops instead of bouncing from each other or shattering like glass. You can drill just few of kilometers before solid rock becomes fluid and fills the hole. Strength of rubber sheet (its ability to handle pressure) depends on its thickness which is linearly proportional to scale factor. Mass of the sheet depends on cube of the scale factor. At some point larger rubber duck can not handle enough pressure to prevent collapse. Also, such a pressure would form duck to a sphere, which is best shape to handle pressure stress, before collapsing.

This would also need energy to break the gravitational binding of the planet. You seem to think at level on which you should not worry too much about realism. In my opinion planet vaporizing lasers would fit well in story which have planet carving drones, Dyson spheres, bigass EmDrives able to move planets etc. totally unrealistic technomagic.

It would be possible to produce energy needed, but not hide it inside a planet or any other structure made of any known material obeying known natural laws. If a neutron star or a black hole would make a near flyby, tidal forces would rip the Earth. Material would be vaporized and ionized to plasma at huge temperatures. Part of it would fall to star, part of it would be converted to radiation energy and part of it would be left as a small cosmic gas cloud.

Planet's gravitational binding energy is about an order of magnitude larger than energy needed to vaporize all mass. Probably any process which would produce enough energy to break gravitational bind would also vaporize material. If our magic laser would only vaporize all mass but not give enough energy to escape, it would stay a gas planet. Excess energy would be radiated during long time and the planet would cool down and condense again.

Such a laser is pure science fiction. No known materials could be used to build it and no known means of store or transport energy could be used. You have to assume so many things against known natural laws that you can get any answer you want. You need certain amount of energy. It is different than power. You can deliver certain energy in short time and high power or in long time and low power. For example, if your magical laser produced 1 s long pulse at 2.5E32 W average power, it would do the job (if we neglect dissipation). But you could also use 10 s long pulse at 2.5E31W or 100 s long pulse at 2.5E30W. Or 660000 years at 3.8E26W (which is Sun's output).

Earth's gravitational binding energy is about 2.5E32 J. Watt is unit of power, which is energy transformed in time unit. Energy is power * time. 2.5E32 J is huge amount of energy. IEA estimated that in 2013 world's energy consumption was 3.9E20 J. If human's could use all energy they produce to send mass out of planet it would take 640 billion years to destroy planet. If it was possible to use whole Sun's power, 3.8E26W, to evaporate Earth, it would take 660 000 years. We can also calculate binding energy per mass. It gives 42 MJ/kg. For example, TNT (and other typical high explosives used in mining or military applications) gives about 4 MJ/kg. If the Earth was made from TNT and it was exploded, gravity would pull combustion products back to spherical planet. https://en.wikipedia.org/wiki/Gravitational_binding_energy https://en.wikipedia.org/wiki/World_energy_consumption

In some sense maybe. But if you calculate lifted tons to orbit or earned money to company, you may get different results. As some already told, there are no good reasons to compare these companies. They have different ways to achieve their objectives and there will certainly be works to do and achievements to get for both companies in rocket launch markets on coming decades. But you can not deny that SpaceX has couple of years lead at current time. It has been years on commercial launch market and lifted tens of payloads to orbit, whereas Blue Origin is still at prototyping phase.

Practical significance would depend on solution. There are many numerical algorithms to calculate approximate solutions for Navier-Stokes equations. If general solution would be simple enough, it would be possible to decrease developing costs but it is not necessarily true. For example, there are some solutions for restricted 3 body problem, which are impractical because numerical algorithms give same accuracy with far less computer time (several order of magnitudes). However, proven existence of these solutions are very important piece of mathematics of such differential equations and in any case solutions of Navier and Stokes equations would be too. It is the reason of prize and possible practical applications would be bonus.

Therefore I mentioned Dragon crew capsule. After it is ready, Falcon 9 can send crew with much lower costs and will be more safe. There are some very special purposes after that, which can not be done with Dragon, but they are not practically needed. Why everyone would want to pay half billion dollars per flight and couple of billions per year fixed costs to have ability to send people to LEO but not to ISS for several weeks? Ability to return satellites have also been useless. They may be different things but they are things which are compared when space missions are planned. There are always much more proposals than actual missions and super expensive Shuttle specialties can not compete with more practical and cheap missions. Therefore NASA made contracts with private companies to develop manned and unmanned rockets to routine missions and retired Shuttles.

The most relevant question is costs per kg on orbit. Other things are artificial records for nerds. In that sense Falcon 9 is overwhelming in most practical purposes compared to Shuttle (except those specialties which exceed Falcon 9's capability, but it is much more cheap and fast to develop Falcon 9 to carry more (Falcon Heavy) or carry crew (Dragon capsule) than to develop Shuttle to compete with Falcons at costs. Shuttle was insanely expensive even with its primitive reusability and it was retired for a good reason. Falcon 9 is very cost effective rocket even when used as expendable. And returning of practically intact first stage with 9 expensive engines, hydraulic systems and fuel tanks gives very promising potential to lower costs significantly.

I think they put new second stage and payload and run first stage again. I do not see any severe obstacles, but of course it needs years if not decades development work and smaller achievements. In that phase there should not be much refurbishment work. Just some basic checks like airplanes have now. Larger refurbishing with in depth tests and replacement of some wearing parts may be needed after 5 or 10 flights. That would give very significant cost advantage compared to current situation. It depends on following development. If SpaceX succeed to develop re-using to give significant time and cost savings, this flight will probably be important milestone for future historians. But if not, this will be one mundane record with countless other very specific technical records. Fortunately it seems that they have now good possibility to success. Their way are clearly much better than any reusing before. Their starting point is very competitive rocket and every improvement in cost efficiency gives more profit and more ability to compete later when other reusable rockets will come into market.

I have never made a spaceplane. I have very probably never landed successfully (without breaking any parts of the plane) on the runway at KSC. I tried planes when I searched desert temple in verion 0.18, but I never came back. I remember that landing was difficult and I never learned to do it right before I lost interesting to plane flying.

Next release seems to be only couple of bugfixes and futile localizations, which are desperate marketing stuff and give nothing in the game. We will see if devs have some real ideas left or not. But to be honest, I am extremely happy. KSP is probably the best entertainment for money I have ever seen. Maybe Factorio will beat it at some day, but I have to play insane amount of hours to be even near.

I do not know but I think that it may be good to compensate wind velocity or part of it, if possible. Landing rocket do not interact with ground or sea, but it moves relative to ambient air.

This is not well defined question. Natural laws we know predicts that any massive thing can not move faster than light (or at light speed). If you put such numbers in equations all results are nonsense. Infinite or imaginary values which have no physical meaning.

Both use several millennia to build billions of huge nuclear bombs with cobolt and other dirty materials. Finally, about in 125th century first bombs begin to hit targets and bombing continues couple of millennia. Both have some defense systems but they are far from perfect and billions of bombs go through. Both civilizations and artificial biospheres are destroyed and all megafauna are extinct. Insects win at Earth and similar small animals at Alpha Centauri and they begin to develop larger and more intelligent until after 539 million years there are interstellar war, episode 2.

Solving the Lambert equation gives you velocity vector in solar coordinates. Ship should have that velocity at boundary of SOI (SOI can be approximated negligible small). You can then transform that location and velocity to planet's coordinates. It gives inclination and other orbital parameters. It should be quite straightforward to calculate burn which gives correct orbit from your parking orbit. The most easy and energy efficient is to use circular parking orbit with correct inclination and LAN.

Why is not correct question. There are no sane reasons to build space colonies. At beginning they are insanely expensive and they do no product anything. At some point they may become self sufficient and begin to grow and develop, but soon after that they demand independence and become competitors to their founders. Expansion is part of human's nature and we do it because we can. First to Moon and Mars and after that to all solid bodies in Solar system which are not exceptionally hostile (like Io on Jupiter's radiation belt or Venus with extreme atmospheric conditions). Maybe there will also be huge space stations on orbit of Sun or planets, but I suspect that humans want to live on solid ground under gravity. Maybe very rich and powerful people can live on earth, quite rich on other planets and larger moons and average people in space stations or on small asteroids in very distant future. I do not believe that Titan is technically or economically better place for the first colony than Mars or Moon. Atmosphere is probably more bad thing than an advantage. Pressure is OK, but temperature is low and dense gas cools everything very effectively. Some of complex hydrocarbon compounds are probably very toxic to humans. They should have very good airlocks and suits to prevent exposure to atmospheric gases. Hydrocarbon atmosphere combined to breathing gases would also form severe fire and explosion risk around every manned building, craft or EVA suit.

I think that oxygen rich atmosphere would be quite probable around ocean planet. Solar ultraviolet radiation breaks water molecules in upper atmosphere and light hydrogen escapes. Soil absorbs some amount of oxygen, but when most elements are oxidized to stable compounds, like on Earth when cyanobacteria began photosyntesis couple of billions of years ago, oxygen absorption ceases and it begins to accumulate in atmosphere. If Jupiter had a large enough moon, like Earth, maybe it could have almost global ocean like Laythe and thick enough atmosphere to keep ocean at liquid state. A significant mass fraction of outer solar system moons are water (much more than Earth have). But certainly such an atmosphere would have too high pressure and oxygen partial pressure for humans.

Compact stars are insanely extreme objects. Gravitational acceleration is a = GM/r^2. Derivation gives change of acceleration per length da/dr = -3*GM/r^3. If we assume solar mass and orbit with radius of 1000 km, da/dr = 400 (m/s^2)/m. So, if astronauts height is 2 m his head is ripped apart from his toes at 800 m/s^2, which would certainly be fatal. But probably radiation and magnetic fields would have killed him far before tidal forces in real life.

Probably you are right, energy wise. But in this case you should think safety wise. Even small hydrogen explosions are very severe safety risks for health and material at typical house environment. Hydrogen is extremely sensitive to explode and it leaks very easily, also through the walls of tubes and containers. You can find pictures from "small" hydrogen explosions, for example battery recharge failures. You do not certainly want such "small" explosion in your home or be near if you are outdoors. You should not store hydrogen for a long time. Small balloons, plastic bottles and plastic bags etc. are best containers for hydrogen. And when you stop your experiments you burn or release all hydrogen. I recommend small adjustable power supply. Something like 3-12 V 1 A cost few tens of euros (or dollars). Electrolysis needs much energy and batteries are too weak and expensive. If you think batteries are more safe use rechargeable NiMH batteries. 2 or 3 cells in series should give suitable voltage. Be sure that you never short circuit rechargeable batteries (for example if your container breaks). They give very high current which can heat cables to red glow and ignite insulation or nearby materials (and of course hydrogen). Use fuse (for example 5 A) as near battery pole as practically possible. It is impossible to give exact times for electrolysis. You should begin carefully with dilute electrolyte and low current and then monitor current, gas flows and warming during process. They change due to reactions on electrodes. Increase current gradually if you are very sure that you equipment can handle it safely. I do not want to sound custodial, but questions like this make me worry. Oxygen is very reactive gas. Everything ignite very easily or even spontaneously (many common oil products) in high concentration oxygen atmosphere, and fires are insanely intensive. And guess what happens if oxygen replaces air between fibers in your clothes and static electricity makes a small spark. If you have a job in which you have to handle oxygen or any other chemicals you have to get suitable safety training. Professionals have to use special tools and infrastructure which are specified to be used with those chemicals they need. It is for good reason. Almost every chemical has its own insidious risks which are often hard to see if chemical is not toxic or if it is necessary for living, like oxygen. If you make hobby experiments you should use Google to find safety information about any chemicals you intend to use and also any reaction products. Material safety datasheets are public data easily available and there are often other safety material for those who work with chemicals. And after that it is always better to play safe. Keep amounts small, reaction rates low, voltages low, work outdoors etc. And think what you do if accident happens before you begin your experiment. How do you extinguish fires without getting electric shock or pouring hot corrosive electrolyte on your clothes. Where do chemicals flow if electrolysis container breaks (because explosion or heat). How do you keep hydrogen and electrolytes away from your electric devices, which I think are not expensive professional models which are specified in explosion or fire hazardous environments. What happens if there will be short circuit which produces sparks, heat and overload to our power supply? Etc.

There could be minimum altitude which would destroy the craft like Kerbol does. Official explanation could be radiation or magnetic field. Limit would be set so that physics do not break. I think that there are no good reason for more than couple of hundreds of km/s orbital velocities. Everything above that would be just huge numbers in mod's code.

Maybe they could have current tanks made from old oil barrels found at junkyard as mark one versions at beginning. Later into game and research player would get little bit lighter, stronger and more polished models. It would need few new parts, but I do not think is it so bad anymore as it was with 32 bit executable.